Are There Illegal MAC Addresses? Can They Cause Issues? or Are There Illegal MAC Addresses? What You

Short answer: No, but...

Long answer: Some MAC ranges are reserved (like for virtual machines), and using them *might* cause issues. ISPs can blacklist MACs if they’re abused.

Spoofing isn’t illegal everywhere, but it’s against TOS for most networks.

Pro tip: VMware and VirtualBox use “locally administered” MACs—good example of legit use cases.